A standard deburring knife as described in German patent 3,740,036 of E. Bermann has an elongated body formed with a trapezoidal-section groove having a pair of angled side surfaces extending parallel to the body's longitudinal axis and a base surface bridging the side surfaces and extending at a small acute angle to the axis, and a trapezoidal-section holder shaped to fit in the groove and of uniform cross-sectional shape, that is with angled side surfaces and a flat base surface bridging them. A blade can be gripped between the base surfaces to project forward from the body and holder. This blade is effectively held since as the holder is moved back it wedges the blade between the base surfaces.
Such a knife is relatively simple but has several drawbacks. First of all, the blade is often not held sufficiently tightly, so that it twists or comes loose when in use. Furthermore the holder part can get lost easily.